Suffering From Headaches, Nausea, Weakness, Palpitations, Frequent Urination. Cure?

hello, I have suffered from headaches for a while now, but they been happening more often. I was thinking it was because i didn t eat, but now the headaches happen when i eat or if i don t. i feel like throwing up. My head feels like is going to explode, weak and sleepy. Also, palpitation including my head gets very hot. When i eat know the headaches feel worse. I been going to the bathroom very often and when i go i have to stay in the toilet because i feel like i do not finish. What could it be and what can i do about it? Thanks..